Characterization and Comparison of Photocatalytic Activity Silver Ion doped on TiO2(TiO2/Ag+) and Silver Ion doped on Black TiO2(Black TiO2/Ag+)

Titanium dioxide (TiO2) is one of the representative ceramic materials containing photocatalyst, optic and antibacterial activity. The hydroxyl radical in TiO2 applies to the intensive oxidizing agent, hence TiO2 is suitable... [ view full abstract ]

Titanium dioxide (TiO₂) is one of the representative ceramic materials containing photocatalyst, optic and antibacterial activity. The hydroxyl radical in TiO₂ applies to the intensive oxidizing agent, hence TiO₂ is suitable to use photocatalytic materials. Black TiO₂was prepared through reduction of amorphous TiO₂ conducting under H₂ which leads to color changes. Its black color is proven that absorbs 100% light across the whole-visible light, drawing enhancement of photocatalytic property. In this study, we aimed to compare the photocatalytic activity of silver ion doped on TiO₂(TiO₂/Ag⁺) and silver ion doped on black TiO₂(black TiO₂/Ag⁺) under visible light range. TiO₂/Ag+ was fabricated following steps. 1) TiO₂ was synthesized by a sol-gel method from Titanium tetra-isopropoxide (TTIP). 2) Then AgNO₃ was added during an aging process step for silver ion doping on the surface of TiO₂. Moreover, Black TiO₂/Ag+ was obtained same as  TiO₂/Ag⁺ except for calcination under H₂. The samples were characterized X-ray diffraction (XRD), UV-visible reflectance (UV-vis DRS), and Methylene Blue degradation test. XRD analysis confirmed morphology of TiO_2. The band gap of black TiO₂/Ag⁺ was confirmed (2.6 eV) through UV-vis DRS, which was lower than TiO₂/Ag⁺ (2.9 eV). The photocatalytic effect was conducted by methylene blue degradation test. It demonstrated that black TiO₂/Ag⁺ had a photocatalytic effect under UV light also visible light.